The 2c capable UFA centers this season are 30+ (Duchene is 34, Tavares/Nelson are 33), none of them are long term just based on age. Bennett and Suter are the only under 30 (at 28), I would see in a 2c role and think to sign for 5 years...and both are probably re-signing with their team before July 1st.
I personally would go the trade route. Hopefully, NYI shows the door to Lou and make Horvat available. Otherwise, if the Wilds sign both Nelson and Boeser like some rumors are saying, that might make Ek available (still 3 years to his contract, 28). And then Lundell would be an amazing add, but doubful he is ever available, even if the Panthers keep Bennett. Seatler might make Stephenson available, if they want to promote Wright too.